Spark-plug.



y Emmi). Ust 1;, 19e-a.

Y W. L. ASH.

`` SPARKYPLUGW APPLICATION FILED OCT. 11, 190;` I

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SPARIGPLUG.

Specification of Letters Patenti.-

Patented Aug. 4. 1908.

Application med october u, isos. serial No. 282244.

To all whom it may concern:

Bo 1t known that I, WILLIS L.\uo.\'r Asn,

having mv oost-etlice address at Lansing,

ex'ilosion, but also as a packing: to prevent L leakage through theopening around the a citizen of the United States, residing and in thecount) of Ingham and State of Michican, have invented certain new anduseful Improvements in Siarlvllugs, of which the I i a cap L wlnch isheld by a lock nut U bearing following is a speci eat-ion.

Mv invention relates to spark plugs for ga'solcne or las engines, andits object is to revent leakage through the plug, diminish iability ofbreakingT the porcelain insulator, and diminish the liability of injuryto the electrode or the insulator by the heat and shock of theexplosion. I attain these 'objects by the construction shown in the'accompanying` drawings, in which Figure 1 isa longitudinal section of myspark plug complete. 4Fig .2 is a partial longitudinal se'ctlon of amodified form on a larger scale. Figs. 3 and 4 show different methods ofconstructing the head of the electrode.l

The body P of my spark plug is of the ordinary construction and isadapted to receive the porcelain'insulator A, said insulator beinerretained in position by the shoulders H and I, which are compressedbetween the WaslierK and the bushing J, as shown in Fig. 1. This washerK is preferably of coper, and acts as a packing to prevent any eakagearound the insulator. The upper extremity B of the insulator is of aconical shape, and the entire insulator is pierced longitudinall with anopening about th of an inch in iameter. Ordinarily it is not advisableor safe to'use` an insulator with so large an openingwas stated above,but the peculiar construction of the electrode emplo ed b me makes itpossible to do this wit 1 per ect safety, and great advantage in. pointof durability and ease of assembly and re air. The. electrode D. passesfreelyl throngl the opening C. On tneupper extremity is either formed orattached an enlarged cap E, towhich is secured the sparking point Q.Between this cap and the extremity of the insulator B is placed acushion or ring of asbestos or similar material which seats'in anannular cuo shaped recess formed in the inner face of the. cap E, onewall of which is defined by the electrode D and the other wall of whichis defined by an inwardly extending flange. vThis cushion serves notonly as an elastic cushion to rotect the point of the insulator from thes lock of the bren ring the porcelain.

frictionally thcreagainst; a dish shaped annuiar spring washer )I titsinside the cap around the electrode D,and between it. and

the body A of the insulator as shown in Fig.

1 to further relieve the shock of the discharge and allow for expansionand contraction of theelectrode D.

s shown in Figs. 2, 3, and -1 the head of my electrode ma) beconstructed in various way?. Thus it may bc formed integrally on thcbody as shown in Fig. 3. er screwed to it as shown in Fig. 4. At resentI much prefer to form the head in l ie `forni of a cup as ,shown inFigs. 3 and 4, but if desired it may lbe constructed in the manner shownin Fig. 2, namely, with a llat lov. er surface: in which case theelastic cushion Ii is preferably rctained in position b v beingr...ibeaded in a slight depressionen the extremity B of the insulator.

This construction, as already stated. enables moto use a largeelectrode. This is of material advantage for several reasons. Itconducts away the heat more rupi-ily from tbe It enables :ne tu securethe electrode in place with screw threads instead of cement, as iscustomarythus scouring a more perfectprotection againstleskagedessliability to destruction by shock, 4which often .produces --lcakage b vbreaking the cement, .and great ease of repairing or replacing theelectrode or insulator in case of injury. The enlarged cap combined withthe elastic cushion and the lange electrode -rod serves to a greatextent to protect the oint of the insulator from the heat. sind alsotrom the shock of the explosion. Besides, their large size and closecontact with the body of the insulator serve t0 conduct the heat rapidlyaway from the point, :1nd thus` oint, thus diminishing the danger of 1.A spark plug embodying an insulator,

formed with a threaded opening receiving .if said elect-rode, a sparkingoint jheyond the (interface of said c osed en sind Cap at its open endbeing fornied with at; annulardrup shaped recess which merges into saidthreaded opening of the rap Wneren a doa'nwardlv hanging protecting sformed an elastic cushion seating in l recess, a second cap havingan-ope:i ing *ciw-:nigh which the opposite end of said electreie passes,an annular ldish shaped sprirg washer perforated and receiving saidinsulator and disposed 'between the last named end of the insulator andthe end of said sse-.ond cap, and a securing nut on the electrwciehearing against said second ca 2- spark plugr embodying an insuiixtor,au elegir-ode passed axially through said in'- suI-atezfr., saidelectrode being pro vided at one end thereof with an enlarged headbearing against the end of said insulator a'nd having 20 a sparkingpoint, said electrode having its other end inreaded, a securing capon'the threaded end of said electrode, saideap havingan auxiliar fia-ngereceiving an d surrounding the adjacent end portion of said insulator 25and an annular dish shaped spring cushioning washer surrounding saidelectrode and received Yn said flange, said Washer being interposedoem-een and lying in Contact with the body of said cap and thendjacentend 30 face of said insulator.

In testimony whereof I affix my signature in presence of two Witnesses.p

XVILLIS LAMONT ASH.

Tit-nessesi E perm: L. LAWRENCE,A Bangs I. CHASE.

